Plumb-bob.



H. D. AIRESMAN.

PLUMB BOB.

APPLIOATION FILED OCT. 19, 1910.

Patented June 20, 1911.

HARRY D. AIRESMAN, 0F SOMERSET, PENNSYLVANIA.

PLUMB-IBOB.

Specification of Letters Patent. Patented June 20, 1911.

Application 'fi1ed October 19, 1910. Serial No. 588,006.

To all whom it may concern.

Be it known that I, HARRY D. AIREsMAN, a citizen of the United States, residing at Somerset, in the county of Somerset and State of Pennsylvania, have invented certain new and useful Improvements in Plumb-Bobs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvements in plumb bobs, and has for an object the provision of a device of this character, the supporting cord of which is contained upon a drum located within the said bob, which is so balanced and constructed that when it is picked up by the said supporting cord this cord will unwind, lowering the hob, and when the said cord is released it will automatically rewind again upon the drum.

Another object of this invention is the provision of a plumb bob which will be comparatively simple in construction and consequently cheap to manufacture.

' WVith the above and various other objects in view, this invention resides in the novel features of construction, combinations, formations and arrangements of parts to be hereinafter more fully described, claimed and illustrated in the accompanying drawing, in which Figure 1 is a vertical longitudinal sectional View of a bob embodying my invention; Fig. 2 is a transverse sectional view taken on the line aa of Fig. 1; Figs. 3, a and 5 are detail perspective views of the shaft, drum and cap attached.

Referring to the drawing by characters of reference, the numeral 1 designates generally a plumb bob of any customary shape, being centrally recessed as at 2, and provided with outwardly extending openings 3 and 4. The upper end of the opening 3 is threaded for the reception of a centrally apertured cap 5, while the opening 4 is adapted to be closed by a curved plate 6, which conforms to the shape of the bob 1 and removably secured thereto by set screws or other suitable fastenings.

A horizontally disposed shaft 7 extends transversely through the recess 2 and supports a drum 8, upon which is wound a cord 9, which passes upward through the aperture in the cap 5 and connects with a end of which is extended through an opening 14 in the shaft 7, while the opposite enlarged end thereof extends through a slot 15, as clearly illustrated in Fig.1 of the drawing. The arrangement of slot and enlarged end of the sprin permits the longitudinal contraction of the said spring, which is necessary when the same is wound tightly, and which would be prevented if the spring were rigidly secured to the drum.

From the foregoing disclosure it will be manifest that the weight of the plumb bob will unwind the cord 9 from the drum 8 when the device is suspended from the ring 10, at the same time winding up the spring 13, which, when the cord is released, will rewind the same through the tension of the said spring.

Having thus fully described this invention, what I claim as new and desire to secure by Letters Patent is:

A plumb bob provided with a centrally located recess, a shaft extending through said recess, a flanged drum rotatable upon the said shaft, a cord wound upon the drum, the said drum being provided with a slot in one side thereof, the said slot terminating in an enlarged opening at the flange, a spring wound upon the shaft and secured at one end thereto,an enlarged head located upon the opposite end of the spring and adapted to be passed through the enlarged opening in the drum and rest against the outer edges of the slot, the said spring being longitudinally movable with respect to the drum, to provide a means for rewinding the cord, the said bob also provided with an opening to permit access to the drum, and a closure for said opening.

In testimony whereof I aflix my signature in presence of two witnesses.

HARRY D. AIRESMAN.

Copies of this patent may be obtained for five cents each, by addressing the Washington, D. 0.

Commissioner of Patents, 

